I need your opinions. I attached 2 pictures of my new pond that was built in January. We have had some real good rains near St Louis MO and the pond level raised and lowered several times. The pictures attached are showing where it sat for a long period and where it got to after we got some flooding rains. However 4 days later it was back down to the lower level. Should I assume its leaking or the ground is saturating? Only reason I am saying saturating is because I was told that by a few pond builders in the area. I am planning on driving 5 hours this weekend to pick up 3-3000lb bags of bentonite because the price is really good on it.

Welcome from another Missourian, Best I can tell form your photos...you lost about a foot of water to "saturation"? That sure seems like a lot to me. My small quarter acre pond took months to fill and never dropped more than a few inches between rains. I would not expect saturation to take the water level back down to a previous level either...if that is your case.

That is what I was thinking I am just hoping that with 9,000 pounds of bentonite I can make a difference. Just don't want to waste time and money

Post-renovation my pond did sort of that thing. Rain, rise, drop a foot, hold there. Rinse and repeat until it was full up.

How far does yours drop after a rain, and does it drop to the same level every time, or is it incrementally rising with each up/down cycle?

If it's consistently dropping to the same elevation you have a leak.

Welcome to the forum from another St. Louis area pond owner. Sorry you didn't join for better reasons.

Sounds you might be one of the luckier ones in the area that gets more rain. It seems to miss me a lot. I've only had I think 2 rain events that helped much but my water shed is a little small.

I feel your pain. My pond has not held water the best but is slowly getting better. I won't get into all the factors of my problem but I would say my main one is compaction.

I would give the pros here all the info you can about your pond and construction of it. How big and deep, what equipment was used, core trench etc.

One of the first things I was told to do is put in a measuring stake to monitor daily loss and see if it is improving.

Hello Jkross and welcome to the forum.

I've helped hundreds of guys on the forum with leaking ponds, and have sealed 7 of own, happy to help if possible.

Some wicking is natural for a new pond, but that would likely not be responsible for 12" loss. Measure your vertical water loss daily with a stake - this is critical data to establish.

Bentonite, in my experience and the pond builders I know, will not seal a hydrated pond. They use bentonite during the construction of liner phase. Sealing hydrated ponds can be achieved in other ways, however.

If you would like to chat I'm happy to spend some time learning about your pond and possible leak issue. My time is free to my Pond Boss family. Feel free to reach out anytime:

tj@hudlandmgmt.com

402.730.4897

I would not waste time and money on Bentonite for a pond that has water in it. It likely will not do any good.

So if I pump the pond out would it then be a good idea to line the bottom with bentonite?

Im a long ways from being a professional but have sealed a few lagoons and ponds up with bentonite and have had way better luck with incorporating it into the soil at least a ft or more deep into the clay, I actually sealed off almost clean sand up that way by mixing a generous amount of it with the sand for about 18" deep, but then that was in a sewage lagoon which only had about a 3 1/2' working depth, not near as much pressure.

Only if you can get a rototiller in there after you spread it out over the pond bottom, and then a compactor to compact the soil.

Do you think a heavy tire bobcat will compact enough?

Question, ""Do you think a heavy tire bobcat will compact enough?"" Probably not. It all depends on clay quality and weight of the bobcat. I assume that the clay quality is not all that good which is why you are using bentonite. It would be better to have very narrow tires than wide tires on a bobcat. A bicycle driven on 4" of soil over an egg will bust the egg whereas a bulldoser on that 4" of soil will not break the egg. Narrow compacts much better than wide tires that spread out the weight for compaction over a wide surface and that is not what you want. Your money is best spent on renting a sheepsfoot roller that is especially designed, built and used to compact soil. Don't go through all this effort and expense to not have the soil compacted as best as possible. The sheepsfoot roller will be a small amount of money as a form of insurance. then if that does not work then you know you did the very best for that attempt. Shop around you might be able to rent a idle sheepsfoot for very reasonable cost. It could 'probably' be pulled with a good quality bobcat.

So I have all the water pumped out.... the ground is wet but I can drive my machine on it. Can I put bentonite down on wet soil or do I need to wait for completely dry

Now that the pond is empty do you see any holes or other signs of where the water has been going?

I'm no pro but the way I understand it you need some dampness to get compaction but to wet and you can't compact it. I would think if the Bentonite gets to wet it will swell before you get it compacted. I would think that you want to get it compacted before it swells to much so it will seal better.

Question while I am trying to prepare to bentonite the bottom I noticed as I am digging in certain concern areas I’m seeing a lot of black dirt under a layer of clay should this have been dug out?

The clay, if used as a liner in the pond, should be 18"-24" thick.

Many years ago I talked to the President/owner of Texas Sodium Bentonite. He said that it had to be tilled into the soil to be of any value.

The operator who built the pond is going to come back out and dig out the black dirt until he gets to clay or rock and start packing in clay. Question is it safe to leave a hill side that the water will be up against untouched or should it be skimmed and packed with clay

If you go by the book you need to line the whole bowl with 24" of clay, done in 6" lifts and compacted. I'm sure that is the best way, but I know it isn't always done that way.